A variety of applications require small and lightweight thermal insulators, in some cases for only a limited time. For instance, in modern-day online commerce, cheese, meat and other temperature-controlled goods are shipped. In the shipping of medicines, proof of temperature-controlled transport of temperature-sensitive medicines has been required for quite some time.
Nevertheless, no technically and economically optimal solutions are yet in use for these applications. Until now, such solutions as chests made of foamed polystyrene (Styropor®) have been used. However, they are costly and typically very bulky for the desired insulating effect. Moreover, disposal of foamed plastics is resource-intensive.
Insulated boxes with integrated vacuum insulation elements, such as are described in DE 10 322,764 A1, offer a better insulating effect. These vacuum insulation elements typically are made of porous material that is evacuated in a jacket. Boxes with these vacuum insulation elements are costly in their manufacture and resource-intensive in their disposal, however. In order to make up for this, therefore, such boxes are typically reused multiple times. Consequently, a return system is necessary in mail-order trade. Therefore, such a solution is not optimal for shipping of goods that tend to be small and/or inexpensive.
EP 1,475,486 describes vacuum insulation elements in which a flat thermal insulating plate made of foam, fiber material, or porous material is evacuated in a metal-coated enclosure.
The manufacture of such vacuum insulation elements requires special equipment, and is complicated and therefore costly. Moreover, disposal and recycling of the materials that are employed are also resource-intensive.
Vacuum insulation elements in the form of flat vacuum insulated panels are also of interest in the construction industry, since they can be made thinner than conventional thermal insulation such as, e.g., sheets of foamed polystyrene, with the same U value (thermal transmittance value).